Chronic hepatitis B surface antigen (HBsAg) carriers run a high risk of developing chronic liver disease after renal transplantation. To determine the impact of liver disease on long-term morbidity and mortality of HBsAg carriers following kidney transplantation we analyzed 1977 patients, including 76 HBsAg carriers, who underwent renal transplantation during the period 1968-1992. Although the HBsAg carriers had a better 5-year patient and graft survival rate (94% and 83%) than HBsAg-negative patients (87% and 61%), the prognosis was poor after the tenth year of transplantation. Transplant loss is more frequently caused by death of the HBsAg carriers, in contrast to the total population (34% vs 17% for HBsAg-negative patients). Death occurs in 73% of cases due to complications of hepatitis B. In the HBsAg-negative patients, the predominant cause of death is cardiovascular failure (51% vs 11% in HBsAg carriers), whereas only 2% died of liver disease. Kidney transplantation in HBsAg carriers with normal liver function appears to be justified because of rare graft loss due to acute rejection, low early morbidity and mortality, and late onset of fatal hepatic deterioration.